In general, glass is an inherently strong material, but the actual strength values of articles made with glass materials are often limited by flaw sizes and distributions within, and at the surface of, these articles. Various processes, including ion-exchange baths, can be used to “chemically” strengthen glass articles. Ion-exchange bath processes, for example, can be used to increase the strength of a glass article by developing a compressive stress layer in a surface region of the article. For example, metal ions in the surface region of an as-produced glass article can be replaced by larger metal ions through ion-exchange processes. These larger metal ions create a local stress field, thereby generating the beneficial compressive stress layer.
Similarly, ion-exchange processes can be used to impart antimicrobial properties in a glass article by injecting certain metal ions, e.g. Ag+, into the surface of the article. The Ag+ ions interact with microbes at the surface of the glass article to kill them or otherwise inhibit their growth. However, the presence of these Ag+ ions and/or the processes used to exchange them in a glass article might alter other characteristics of the glass articles (e.g., the compressive stress distribution in a chemically-strengthened glass substrate). Yet at the same time, relatively high levels of Ag+ ions at the surface of the glass articles are required for acceptable antimicrobial performance. Further, Ag+ ion precursors are relatively expensive materials to obtain and process.
Accordingly, there is a need for new processes for efficiently making strengthened glass articles with antimicrobial capabilities that do not significantly alter other performance attributes of these articles.